Subsolar point

The subsolar point on a planet is where its sun is perceived to be directly overhead (in zenith).

For planets with an orientation and rotation similar to the Earth's, the subsolar point will move westward, circling the globe once a day, but it will also move north and south between the tropics over the course of a year. Potentially any point in the tropics could be subsolar. The winter solstice (in the northern hemisphere) occurs when the subsolar point is over the tropic of capricorn and the summer solstice is at the instant when the subsolar point is over the tropic of cancer.

The subsolar point on a body in the solar system is where the sun's rays are hitting it exactly perpendicular to its surface; or on an object in space, the point that is closest to the sun.